Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare read-only, idempotent, non-destructive behavior, so the description doesn't need to restate that. It adds useful operational context: the data source, authentication requirements, API key requirement, and cost. It doesn't describe default behavior when no query is passed, but that is a minor gap for a read-only tool with a schema-provided limit default.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact, front-loaded with the core purpose, and each sentence earns its place: what it does, how to use the query, when to prefer another tool, and required setup. There is no filler or repetition of schema property names.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only lookup with two fully documented optional parameters and an output schema, the description covers the essential context: purpose, query semantics, routing to alternatives, authorization, cost, and API key requirement. Nothing material is missing for correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Input schema coverage is 100%, so limit and query are already documented. The description adds 'semantic/keyword retrieval' to clarify the query's role, but this mostly rephrases the schema's 'Semantic focus' field without adding new format or edgecase semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description identifies the exact resource ('memories'), the operation ('retrieve'), the ownership scope ('authenticated user'), and immediately distinguishes it from the sibling 'search' tool. An agent can confidently tell this apart from the other get_* and search tools without opening schemas.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It provides an explicit branching instruction: 'Prefer search for event-first trip and calendar titles.' It also tells the agent when to pass the query argument and lists prerequisites (OAuth/scoped credential, API key, cost), leaving little ambiguity about invocation setup.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.